﻿using System;
using System.Security.Cryptography;
using System.IO;

namespace LuDragon.Common.Utils
{
    /// <summary>
    /// 加密解密实用类。
    /// </summary>
    public class Encrypt
    {
        //密钥
        private static byte[] arrDESKey = new byte[] { 42, 16, 93, 156, 78, 4, 218, 32 };
        private static byte[] arrDESIV = new byte[] { 55, 103, 246, 79, 36, 99, 167, 3 };

        /// <summary>
        /// 加密。
        /// </summary>
        /// <param name="m_Need_Encode_String"></param>
        /// <returns></returns>
        public static string Encode(string m_Need_Encode_String)
        {
            if (m_Need_Encode_String == null)
            {
                throw new Exception("Error: \n源字符串为空！！");
            }
            DESCryptoServiceProvider objDES = new DESCryptoServiceProvider();
            MemoryStream objMemoryStream = new MemoryStream();
            CryptoStream objCryptoStream = new CryptoStream(objMemoryStream, objDES.CreateEncryptor(arrDESKey, arrDESIV), CryptoStreamMode.Write);
            StreamWriter objStreamWriter = new StreamWriter(objCryptoStream);
            objStreamWriter.Write(m_Need_Encode_String);
            objStreamWriter.Flush();
            objCryptoStream.FlushFinalBlock();
            objMemoryStream.Flush();
            return Convert.ToBase64String(objMemoryStream.GetBuffer(), 0, (int)objMemoryStream.Length);
        }

        /// <summary>
        /// 解密。
        /// </summary>
        /// <param name="m_Need_Encode_String"></param>
        /// <returns></returns>
        public static string Decode(string m_Need_Encode_String)
        {
            if (m_Need_Encode_String == null)
            {
                throw new Exception("Error: \n源字符串为空！！");
            }
            DESCryptoServiceProvider objDES = new DESCryptoServiceProvider();
            byte[] arrInput = Convert.FromBase64String(m_Need_Encode_String);
            MemoryStream objMemoryStream = new MemoryStream(arrInput);
            CryptoStream objCryptoStream = new CryptoStream(objMemoryStream, objDES.CreateDecryptor(arrDESKey, arrDESIV), CryptoStreamMode.Read);
            StreamReader objStreamReader = new StreamReader(objCryptoStream);
            return objStreamReader.ReadToEnd();
        }



        /// <summary>
        /// 32位MD5加密
        /// </summary>
        /// <param name="strText">要加密字符串</param>
        /// <param name="IsLower">是否以小写方式返回</param>
        /// <returns></returns>
        public static string MD5Encrypt(string strText, bool IsLower)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] bytes = System.Text.Encoding.UTF8.GetBytes(strText);
            bytes = md5.ComputeHash(bytes);
            md5.Clear();

            string ret = "";
            for (int i = 0; i < bytes.Length; i++)
            {
                ret += Convert.ToString(bytes[i], 16).PadLeft(2, '0');
            }

            return ret.PadLeft(32, '0');
        }
    }
}
